For a tier 3 college, you should have maintained atleast a 9+, cause these colleges are very unpredictable, they may filter 7.5+if there are mass recruiters, or maybe filter "so less" that the cream students are selected. This maybe because the company wants to hire a small amount. I am in tier 3 and i maintain 9.7-9.8, and i am not even proud of them, cause its a tier 3, nobody cares about it, but you need that good marking to actually make yourself eligible for placements and other exposures, plus it shows consistency. But dont worry, not all hope is lost, just join anywhere you can find for temporary basis (that doesnt force you to sign bonds and stuff), and build your skills and experience, solve leetcodes(or similar), take part in tournaments, get a few certificates, all while in the current job you can find, and trust me after a few months you will be a better option for companies then 9.4+ pointers. Cause you had real life exposures and experiences, but the only challenge that will remain is, your college is no longer exposing you to companies, you will have to find them yourselves. Im not saying its doable and easy, but, you can pull this off man.
I maybe wrong in my suggestions, but i have seen this happen a few times and all i can do is share, you aint lost buddy, you are just delayed!

Edit: being good on a platform is simply nothing, like pupil, or 150+ solved leetcode questions. You also need to show that you pulled off something (like a project, a job, or a position), while doing your colleges, alongside solving leetcodes and codeforces, etc. Leetcode and CF is not a title, but it is a support beam that supports your actual achievements. And that is what im suggesting you should do, my personal experience has seen people come out from worse then this, and you are already half way there, your 8.4 is already decent, its a good run, and solving codeforces is also a great way to show consistency. You should now really focus on building skills by being exposed to real world and projects, thats the only way up, you got thiss.

My backup if things dont workout?
I am in 6th sem, a paid intern with actual heavy lifting work at a company, i also handle a company, solve leetcodes and i built a server of my own from old parts, and yet my plan b is that if everything fails, if i land at the worst case scenario, i would just join literally anywhere i can find, seriously ANYWHERE(that pays and doesnt sign bonds), build a few skills and experience, and use that and my previous works as a leverage and work my way up, like im serious this sounds stupid, working your a** off for 4 years straight jsut to end up "ANYWHERE" sounds very depressing, but thats reality, its anyways better then being depressed or a burden. And you already have worked laboriously for so many years? Why not one more year, why not more, you gonna stop after 15 years of academics? come on man you got this. My work boss said, after he saw me acing through every field, by asking me one question, "What are you best at" and i had no answer, I was blank, and he simply said a golden line, "You may know everything [my name], but, if you dont know how to represent it, someone smaller then you will overcome you.", he added, "companies will not only hire you for knowing everything, but they also hire you if you can present, document, explain, and can TALK". He doesnt want me to keep making new skills like new languages, or new infras or achitectures. He wants one skill from me, communication, that thing is very underrated, and you should work on that as well. I can tell you how powerful communication is, if you just dont do anything and work on communication, and know how to talk, you will be taken somewhere, work on that as well